Disconnecting contact



wlTNEssEs:

Nov. 3, 1942.' a. l. HAYFoRD 2,300,393

' DIscoNNEcTING CONTACT 'Filed may 14, 1941 fQ-f l 14 Patented Nov. 3,1942 to Westinghouse Electric la Manufacturing Company, Ea'st`Pittsburgh, Pa., a corporation of Pennsylvania` `appagante May 14, 1941,serial 110.3935112 -5 claims. (ci. 173-363) r My invention relates,generally, to electric switches and, more particularly, to thedisconnecting contact members of electric switches suitable fordisconnecting removable circuit breakers from the current conductors ofa power` system.

The conventional disconnecting contact assembly for metal cladswitchgear, as manufactured at the present time by the manufacturers ofrswitchgear apparatus, utilizes circular or garter springs wrappedaround the contact segments or fingers to exert radial contact pressure..With springs of this type there is a possibility of one of thembreaking and, wheny straightened out, being of sufficient length toground the circuit breaker or the bus.

An` object of my invention, generally stated, is to provide adisconnecting contact which shall be simple and eflicient in operationand which may be economically manufactured and installed.

A more specific object of my invention is to provide a disconnectingcontact suitable for connecting round current conducting members.`

Another object of my inventionis to provide for utilizing fiat springsto apply radial pressure to the contact lingers of a disconnectingcontact of the circular type.

A further object of my invention is to enclose the contact members of acircular disconnecting contact.

Other objects of my invention will be explained hereinafter or will beapparent to those skilled in the art.

According to my invention, the contact members of a disconnectingcontact of the circular type are enclosed by a cylindrical sleeve whichalso functions to maintain the contact fingers in spaced relation. Afiat spring is disposed between 'each of the contact fingers and thesleeve i tially in elevation, of a disconnecting contact embodying myinvention;

Fig. 2 is a sectional view, taken along the line II-II of Fig. l; and

Fig. 3 is a view, in perspective, of one of the contact fingers and itscooperating spring member.

Referring to the'drawing, and particularly to Fig. l, the disconnectingcontact shown therein is comprised of two parts, a moving contact IG anda stationary contact I I. The stationary contact II'may comprise a roundstud I2 which is'.

mounted in a parcelain bushing I3. The stud I2 is provided with ashoulder IrlV which is disposed on one side of a partition i5 in thebushing I3 and a nut I6 which may be screwed up against the other sideof the partition I5, thereby securely fastening the stud I2 in thebushing I3.

The movingcontact Iii may comprise a stud Il which may be part of acircuit breaker structure (not shown) anda plurality of contact ngers I8disposed around the periphery of the stud I'l, The contact fingers itare enclosedv by a sleeve I9, which is preferably composed of steel orother suitable material.

As shown in Fig. 3, an individual spring 28 is provided for each onel ofthecontact iin-gers I8. Each end of the spring 20 is slotted andportions 2l of the spring are bent over to engage the sides of thecontact finger, thereby retaining the 1inger and the spring in assembledrelation. As shown in, Fig. l, the metal sleeve I9 is provided with aninwardly extending projection 22 which has notches 23 for receiving thesprings 20, thereby maintaining the Contact lingers I8 in spacedrelation around the periphery of the stud Il. In this manner the springs20 function to maintain contact pressure between the fingers I8 and thestuds I2 and il, as well as to retain the contact ngers in spacedrelation.

A groove 24 is provided in the stud I'I for receiving an inwardlyextending projection 25 on each of the contact fingers I8, therebyretaining the lingers on the stud I1 when the moving Contact I8 isdisengaged from the stationary contact I I. It will be noted that thegroove 24 is slightly wider than the projection 25 on the contact ngersI3. In this manner a predetermined amount of longitudinal movement ofthe contact fingers I8 with respect to the stud I1 is permitted, therebyproviding a wiping action between the contact fingers I8 and the studI1. However, the longitudinal movement is limited by the groove 24 andthe projection 25.

In order to prevent collapsing of the contact lingers I8 when they aredisengaged from the stud I2, the sleeve I9 is provided with an inwardlyextending flange 26 which is disposed to engage an extension 2'I on eachof the springs 20. As explained hereinbefore, the portions 2| of thesprings 20 rmly grip the contact fingers I8. In

this manner the radial movement of the contact ingers is limited by theflange 25 on the sleeve I9 and the extension 21 on the spring 20, andcollapsing of the Contact ngers is prevented.

From the foregoing description it is apparent that I have provided adisconnecting contact assembly which is full floating and permitsrelative niisalignment between the moving contact Hl and the stationarycontact H. Furthermore, the use of flexible shunts in the contactstructure is entirely avoided since the current is conducted between thestuds l2 and I1 by the bridging contact members I8 which are of a rigidconstruction. I have also eliminated the use of circular or gartersprings which, as explained hereinbefore, may cause serious trouble inthe event of breakage of one of the springs. The enclosing sleeve hereindescribed not only cooperates with the at springs to maintain thedesired contact pressure, but also aiords protection for the currentconducting parts of the contact assembly.

Since numerous changes may be made in the above described constructionand different embodiments of the invention may be made without departingfrom the spirit and scope thereof, it is intended that all mattercontained in the foregoing description or shown in the accompanyingdrawing shall be interpreted as illustrative and not in a limitingsense.

I claim as my invention:

1. A disconnecting contact comprising, a round stud, a plurality ofcontact fingers disposed around the periphery of and supported by saidstud, means on the stud cooperating with means on the ngers for limitinglongitudinal movement of the fingers, a tubular sleeve surrounding theiingers. means on said sleeve for retaining the ngers in spacedrelation. resilient means disposed between said sleeve and said iingersfor maintaining contact pressure between the stud and the fingers. andextensions on said resilient means for engaging opposite sides of saidfingers to retain them in the sleeve.

2. A disconnecting contact comprising, a round stud, a plurality ofcontact ngers disposed around the periphery of said stud, means on thestud cooperating with means on the fingers for limiting longitudinalmovement of the iingers, a cylindrical sleeve surrounding the fingers,internally projecting means on said sleeve for retaining the iingers inspaced relation, and a spring disposed between each of said fingers andthe internally projecting means on said sleeve for maintaining contactpressure between the stud and the fingers.

3. A disconnecting contact comprising, a round stud, a plurality ofrigid contact fingers disposed around the periphery of and supported bysaid stud, a tubular sleeve surrounding the fingers, an individualspring for each contact nger disposed between the finger and the sleevefor maintaining contact pressure between the stud and thefinger, meanson said springs for engaging said fingers, and means on said sleeveengaging said springs to retain the fingers in spaced relation.

4. A disconnecting contact comprising, a round stud, a plurality ofrigid contact ngers disposed around the periphery of said stud, acylindrical sleeve surrounding the ngers, an individual spring for eachcontact finger disposed between the finger and the sleeve formaintaining contact pressure between the stud and the finger, and meanson said springs for engaging said lingers to retain them in spacedrelation, said springs being disposed in notches provided on the innersurface of said sleeve.

5. A disconnecting contact comprising, a round stud, a plurality ofrigid contact iingers disposed around the periphery of and supported bysaid stud, a cylindrical sleeve surrounding the fingers, an individualspring for each contact linger disposed between the iinger and thesleeve for maintaining contact pressure between the stud and the finger,means on said springs for engaging said fingers, and means on saidsleeve engaging said springs to retain the iingers in spaced relation,said sleeve having an internal fiange disposed to engage one end of saidsprings to limit the radial movement of said iingers.

BENJAMIN I. HAYFORD.

